Thermostat



FIG. 1 is a perspective view of a thermostat embodying the present inventive design;

FIG. 2 is a top plan view of the thermostat of FIG. 1;

FIG. 3 is a front elevational view;

FIG. 4 is a rear elevational view;

FIG. 5 is a bottom plan view;

FIG. 6 is a left side elevational view; and,

FIG. 7 is a right side elevational view. 

The ornamental design for a thermostat, as shown and described. 